The invention relates to a robot tool for placing sealing plugs into openings in an automotive body component, in particular also for placing the sealing plugs into openings in regions that are difficult to access. The invention furthermore relates to a method for placing sealing plugs into an opening in an automotive body component, using the robot tool.
In order for liquid paint, after painting, to be able to rapidly flow out of the cavities in automotive body components, the latter are provided with numerous, in some instances up to a few hundred, openings. Bores are also to be provided for locating welding spots. Moreover, wax for sealing the automotive body component can be injected into the cavities through these openings. All of the openings have to be closed again during assembly, so as to prevent the ingress of moisture or water, respectively, and to protect the vehicle against corrosion during operation. The openings are closed by way of so-called sealing plugs of a plastics material, there being various diameters of said sealing plugs. The sealing plugs are, in most instances, inserted manually into the openings by operators.
This handling mode has various disadvantages. The operation is not ergonomic for the operator placing the sealing plugs, since said operator has to bend down and stretch out in order for the sealing plugs to be placed. Moreover, a significant amount of force is required in order for the sealing plug to be pushed into the respective opening, which is very laborious in the long run. This can lead to a loss of concentration and thus to a higher susceptibility to errors. Since up to a few hundred sealing plugs have to be placed, depending on the vehicle model, the sealing plugs are repeatedly positioned by various operators at different stations that are distributed throughout the production process. This requires many hand movements which have to be learned by innumerable different operators during a significant amount of training time.
On account of the various diameters of the sealing plugs there is the possibility of the latter being wrongly placed in individual cases. However, it also cannot be excluded that the respective sealing plug is indeed placed at the correct location but is not pushed into the automotive body with sufficient force and thus does not provide complete sealing (or even drops out when the vehicle is in motion). Individual sealing plugs can also be simply forgotten. On account thereof, moisture or water can get into the automotive body, leading to corrosion.
Finally, the openings are bores with sharp edges on which the operator could be injured when placing the sealing plugs.
There are also robot-supported methods for inserting the sealing plugs. However, in each case only one sealing plug can be received herein on the placing installation of the robot tool. Furthermore, a reverse movement to the reloading magazine has to be performed once each sealing plug has been placed. Much time is lost on account thereof.
Also, the robot tool operates by vacuum or compressed air, respectively, and apart from the electrical connector also requires a supply of air. The provision of compressed air is generally very energy intensive. Furthermore, on account of the necessary use of compressed-air hoses, there is the risk of entanglement or tripping, respectively, that is to say of injury.
It is also disadvantageous in the case of robot tools used to date that the latter are not adapted for human-robot interaction. The robot station is fenced in such that no human can work on the automotive body component while the sealing plugs are being placed. A tool adapted for human-robot interaction has to be designed in a manner corresponding to lightweight-construction robots, so as to have an output and force limitation according to the definition as per DIN ISO 10218, part 1 & part 2, in order for a collaborating operation as per TS-15066 to be enabled. It is important herein that there is no risk emanating from the potential actuators of the tool.
It is also disadvantageous that the vacuum head of the robot tool that is usually used is not interchangeable. In each case only one specific sealing plug having the diameter that matches the vacuum head can thus be used. Once the sealing plug has been placed, confidence is then placed in a good fit, without any post-checking being provided. Should the sealing plug fail to hold, moisture can ingress, as has been described.
It is furthermore problematic that sealing plugs also have to be placed in regions of the vehicles that are difficult to access, for example on the vehicle underbody. It is required to this end that the tools employed have an axial extent that is as short as possible, so as to be able to be employed in narrow spacings from or intermediate spaces to, respectively, the vehicle.
The invention is therefore based on the object of providing a robot tool having minimal space requirements, by way of which sealing plugs can be placed in a rapid and variable manner and without continual reloading even in regions of the vehicle that are difficult to access, guaranteeing a durable fit of the sealing plugs. It is furthermore an object of the invention to provide a method by which the sealing plugs can be placed with minimal space requirements by the robot tool in a more rapid manner and in regions of the vehicle that are difficult to access.
According to the invention, a robot tool for placing sealing plugs into openings in an automotive body component is provided. The robot tool has a placing installation on which a sealing plug magazine having a multiplicity of lined-up sealing plugs, which by means of the placing installation are capable of being placed in a directly sequential manner and without reloading into the respective openings of the automotive body component, is disposed. The sealing plugs, by way of a drive unit, are capable of being ejected in predefined steps from the sealing plug magazine that is received in the placing installation. The sealing plug magazine extends axially in an axial direction, and the drive unit is disposed on the sealing plug magazine at an angle α of 90-150°, in particular 90-120° in relation to the axial direction.
Compared to an exclusively linear arrangement of the drive unit and of the sealing plug magazine in the axial direction, the installation space required for the robot tool, said installation space having a drive unit that is disposed so as to be angled relative to the sealing plug magazine, is significantly reduced such that even regions that are difficult to access, such as the vehicle underbody, can be populated with sealing plugs. The tool overall becomes more compact.
In one advantageous variant embodiment of the invention, it is furthermore provided that the drive unit comprises a motor and a flexible brush cable that is configured as an indexing element, wherein the brush cable is connected to a slide which is capable of being repositioned in the first direction and by way of which the sealing plugs are capable of being moved or ejected, respectively, out of the sealing plug magazine. The use according to the invention of a flexible brush cable solves the issue of the drive unit and sealing plug magazine construction elements that are disposed in an angled manner, and enables indexing of the slide in the axial direction, despite the drive unit being disposed so as to be oblique to the sealing plug magazine and thus to the sealing plugs that are stacked therein. A flexible helical shaft is defined as a “brush cable”.
An embodiment in which the brush cable has a deflection at an angle β of 60-120°, in particular of 80-100°, furthermore preferably of 90°, is particularly favorable.
In one embodiment, the drive unit comprises a drive element which engages the brush cable and during operation moves said brush cable such that the latter repositions the slide. The drive element to this end has force introduction elements, for example teeth, which engage in complementary receptacles that are provided on the brush cable and move the brush cable along the deflection.
It is provided in one refinement of the invention that an encircling elastic lip, which holds the sealing plugs in the sealing plug magazine and by way of an axial movement of the sealing plugs is capable of being elastically bent in the axial direction of the robot tool, is provided on an outlet of the placing installation. The integration of the sealing plug magazine and of the placing installation enables a multiplicity of sealing plugs to be sequentially placed without the placing installation having to repeatedly pick up an individual sealing plug. A rectilinear and ideally guided ejection is guaranteed by guiding the sealing plugs by way of an exact fit in the sealing plug magazine. The integration of the elastic lip guarantees reliable installation of the sealing plugs at the respective opening and retains the respective successive sealing plug in the sealing plug magazine. On account of the elasticity, there is no mechanical action on the sealing plug per se, such that the assembly does not influence the predefined and established properties of the sealing plug.
In one advantageous variant embodiment it is furthermore provided that the elastic lip on the placing installation is disposed so as to be axially spaced from an external axial periphery of the placing installation. The spacing guarantees a planar bearing of the placing installation on the component to be provided with the sealing plug prior to the sealing plug being placed and thereafter. It is provided in one embodiment according to the invention that the sealing plugs in each case have one non-elastic cover, wherein the frontmost sealing plug in the sealing plug magazine in the region of the placing installation is held by the elastic lip. The elastic lip encompasses the cover of the sealing plug and fixes said cover in a positionally accurate manner in the sealing plug magazine. The fact that the cover is non-elastic enables a predefined shape which remains unmodified during the assembly.
The elastic lip bears on the respective cover of the frontmost sealing plug, and is bent back by the cover in the course of the ejection movement of the sealing plug. As soon as the sealing plug has been placed on the component, the elastic lip folds back into the placing installation and holds the successive sealing plug in the magazine. The elastic lip guides the sealing plug in the axial placing direction during the placing movement and prevents canting or an oblique penetration of the opening of the component.
In one preferred embodiment of the invention it is furthermore provided that the robot tool is adapted for human-robot interaction and the placing installation is capable of being guided sequentially to the respective openings in order for the sealing plugs to be placed. The positioning can be performed so as to be automatically based on a camera or by any other arbitrary method known in the prior art (for example, a force-regulated positioning of the robot, positioning by means of sensors, (capacitive, proximity switch, light sensor, etc.)). The placing installation herein is guided to the opening, while the insertion of the sealing plug is performed by machine force. By way of the design adapted for human-robot interaction it is also enabled that, apart from placing sealing plugs, other operations can also be carried out simultaneously on the automotive body component and that the placing of the sealing plugs is capable of being integrated into further assembly procedures.
In one favorable exemplary embodiment, the invention furthermore provides that the sealing plugs, by way of an electric spindle drive, are capable of being ejected in predefined steps from the sealing plug magazine that is received in the placing installation, for example by using a spindle motor. On account thereof, it is possible for the sealing plugs, prior to and during the placing procedure, in terms of the penetration depth to be positioned precisely in the opening. Also, a preliminary (preloading) position can be guaranteed for an improved introduction of the sealing plugs into the opening.
According to the invention, the placing installation of the robot tool in one exemplary embodiment is embodied so as to be interchangeable such that dissimilar sealing plugs are placeable into respectively dissimilar openings. Various sealing plug sizes and sealing plug configurations can be placed, depending on the automotive body and depending on the opening.
The invention furthermore relates to a method for placing the sealing plugs into the openings in the automotive body component, using the above-described robot tool, and is distinguished in that the sealing plug to be placed is first ejected from the outlet of the placing installation by a predetermined measure by way of the spindle drive of the placing installation, and the partially ejected sealing plug by means of the placing installation is inserted into the opening to be closed such that part of the sealing plug engages in the opening from behind so as to be held therein. The sealing plug is finally ejected from the placing installation, and the placing installation is retracted, wherein the sealing plugs by way of the drive unit are ejected in predefined steps from the sealing plug magazine that is received in the placing installation, while the sealing plug magazine extends axially in a first direction, and the drive unit is disposed on the sealing plug magazine at an angle α of 90-170° in relation to the first direction.
A method step according to which, in order for the sealing plug to be placed, the placing installation is switched so as to freely oscillate such that the sealing plug by way of the oscillating movement of the placing installation and of components connected thereto is positioned in a self-acting manner so as to be centric to the opening to be closed, is favorable herein. It is advantageous herein if the sealing plug has a conical configuration in the region to be introduced into the opening.
By utilizing the robot tool according to the invention and the respective method, no human has to carry out any movement that is unfavorable to him/her in terms of ergonomics. The effort in terms of force for placing the sealing plugs is performed by the machine. Owing to the fast placing procedure, many different operators no longer have to be tasked with inserting the sealing plugs. Training time and planning time, that is to say time during which the operator is busy with installation work on each vehicle, is saved. The insertion of the sealing plugs by the robot is performed much more rapidly than is the case with manual labor, on account of which costs can be saved. Furthermore, the robot always places the sealing plugs at the correct location, independently of the diameter of said sealing plugs. Errors can thus be reduced and the quality of placing can be increased. Finally, the operator is no longer in contact with the sharp-edged openings and can thus no longer be injured on the latter. On account of the angled embodiment of the sealing plug magazine and of the drive unit, regions of the vehicles which are difficult to access and offer only limited space for the use of a tool can also be provided with sealing plugs.
As opposed to previous robotic tools, on account of the lining up of a plurality of sealing plugs in the sealing plug magazine, it is no longer necessary for a new sealing plug to be picked up after each insertion procedure. Time and costs can thus be saved. By using the spindle drive and by omitting the compressed-air vacuum mechanism, energy and costs are saved on the one hand, and the compressed-air hoses can also be omitted, on the other hand. The complexity and the risk of injury are minimized on account thereof.
By way of the placing installation that is designed to be replaceable, the robot tool can be adapted to the respective requirement or to the respective diameter of the sealing plug, respectively. The robot tool is thus universally employable.
In as far as technically possible, all above-described features can be freely combined with one another.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.
The figures are exemplary and schematic. The same reference signs identify the same parts in all views.